#11: Django 2.0 is dropping Python 2 entirely, pipenv for profile functionality, and Pythonic home automation

This is Python Bytes, Python headlines and news deliver directly to your earbuds: episode 11, recorded on January 30th, 2017.

#1 (Brian) pipenv - Pipfile, pip, and virtualenv

• announcement from Kenneth Reitz
• reddit thread
• Features
  • Automatically finds your project home, recursively, by looking for a Pipfile.
  • Automatically generates a Pipfile, if one doesn't exist.
  • Automatically generates a Pipfile.lock, if one doesn't exist.
  • Automatically creates a virtualenv in a standard location (project/.venv).
  • Automatically adds packages to a Pipfile when they are installed.
  • Automatically removes packages from a Pipfile when they are un-installed.
  • Also automatically updates pip.

#2 (Michael): Django 2.0 is dropping support for legacy Python

• Django changing docs to default to Python 3
• The next release, Django 1.11, will be a long-term support release, and the one after that, Django 2.0, will no longer support Python 2.

#3 (Brian) attrs

• Hynek Schlawack
• pypi: https://pypi.python.org/pypi/attrs
• readthedocs: https://attrs.readthedocs.io/en/stable/overview.html
• I know this has been around for a while. But I’ve just stumbled across it while reading a blog post about requests, which was good, but we’ve covered requests a lot lately, so I’m gonna skip that article today.
• pip install attrs, with an s, even though you import without the s
• Does all of the grunt work of writing dunder functions for you so you can write classes with a small amount of code that behave like classes and objects should. Especially if you come from a C++ background, this makes writing classes more intuitive.

#4 (Michael): Go faster Python

• This blog post gives an introduction to some techniques for benchmarking, profiling and optimising Python code.
• If you have a Python program that’s running slowly, what are your options?
  • Benchmarking and profiling
    • Our intuition is often wrong
  • Benchmarking: %time, %timeit, timeit
  • Function profiling: %prun, cProfile
  • Line profiling: %lprun, line_profiler (requires line_profiler)
  • Cython

#5 (Brian): Getting Python 3 into distributions

• Not an article but a couple of pleas.
• Many OS distributions, including Red Hat, ship with Python 2.7.
• Many developers don’t have the authority to install Python 3.x for projects.
• Two pleas:
  • distributions: ship with both if you have to, but let 3.6 be an option for people.
  • companies: install Python 3.6 and let some projects use that
• We can’t just encourage users to switch to Python 3 if it’s not their choice.

#6 (Michael) Home Assistant

• Home Assistant is an open-source home automation platform running on Python 3.
  • Track and control all devices at home and automate control
  • Installation in less than a minute.
  • Observe: Track the state of all the devices in your home, so you don't have to.
  • Control: All your devices from a single, mobile-friendly, interface.
  • Automate: Setup advanced rules to control devices and bring your home alive.
    • have the lights turn on when the sun sets and you are home?
    • have the lights turn on when anyone comes home and it is dark?
    • dim the lights when you start watching a movie on your Chromecast?
    • receive a message when the lights turn on while you are not at home?
• Demo: https://home-assistant.io/demo/
• aiohttp: Asynchronous HTTP Client/Server